The present invention relates to internal combustion engines, and more particularly, but not exclusively, is directed to operating techniques for a turbocharged internal combustion engine driving an electrical power generator.
In certain applications it is generally desirable to control rotational speed of an internal combustion engine. This is particularly true in applications where the engine is a prime mover for an electrical power generator. Often, proper performance of electrical equipment being powered by such a generator requires that alternating current (AC) be provided at a generally constant frequency, despite changes in generator load, operating conditions of the engine, etc.
Previous attempts have typically utilized one particular engine control subsystem, such as throttle control, to maintain engine speed at a desired speed setpoint, while simultaneous utilizing other control subsystems to optimize different parameters. However, such systems still allow engine speed variations that may be unacceptable for certain applications. Thus there is a need for a technique that more accurately regulates engine speed. Also it would be particularly advantageous if this need could be met using an engine capable of operation with a gaseous fuel because of its ready availability in many locations that require a back-up power generation system and its potential to be less adverse to the environment compared to other fuel types. Moreover, other internal combustion engine applications would benefit from better techniques for regulating engine speed. The present invention meets these needs and provides other benefits and advantages.